The following description of the background of the invention is provided to aid in the understanding the invention, but is not admitted to be or describe prior art to the invention.
NF-κB is a ubiquitous transcription factor that plays a prominent role in the activation of the immune system and in stress responses by regulating the transcription of many early, inducible genes including proinflammatory cytokines, adhesion molecules, growth factors, enzymes, and receptors (Ghosh S., May, M. J., and Kopp. E (1998) Annu. Rev. Immunol. 16, 115-260; Zandi, E., and Karin, M. (1999) Mol. Cell. Biol. 19, 4547-4551; Karin, M. (1999) J. Biol. Chem. 274, 27339-27342). Specificity of gene expression is determined at a cellular level by a diverse array of external stimuli such as bacterial products including LPS, as well as cytokines, most importantly tumor necrosis factor-α (TNFα) and interleukin-β (IL1β). Through the synergistic interaction with other transcription factors, further specificity can be achieved while maintaining enormous potential to coordinately induce a large number of functionally related genes. NF-κB is composed of homo and heterodimers of the Rel protein family and is sequestered in an inactive form in the cytoplasm by members of the IκB family of inhibitory proteins (Ghosh S., May, M. J., and Kopp. E (1998) Annu. Rev. Immunol. 16, 115-260; Zandi, E., and Karin, M. (1999) Mol. Cell. Biol. 19, 4547-4551; Karin, M. (1999) J. Biol. Chem. 274, 27339-27342). IκBs mask the nuclear localization signal on NF-κB, preventing nuclear translocation and hence DNA binding to the promoter regions of responsive genes. Stimulation of cells with an agonist that activates NF-κB leads to a series of biochemical signals, ultimately resulting in the phosphorylation, ubiquitinylation, and degradation of IκBs, thereby releasing NF-κB for nuclear translocation (Ghosh S., May, M. J., and Kopp. E (1998) Annu. Rev. Immunol. 16, 115-260; Zandi, E., and Karin, M. (1999) Mol. Cell. Biol. 19, 4547-4551; Karin, M. (1999) J. Biol. Chem. 274, 27339-27342). Recently, two IκB kinases (IKK1 or IKKα and IKK2 or IKKβ), which phosphorylate IκBs and thereby initiate their degradation, have been cloned and characterized by a number of laboratories (Ghosh S., May, M. J., and Kopp. E (1998) Annu. Rev. Immunol. 16, 115-260; Zandi, E., and Karin, M. (1999) Mol. Cell. Biol. 19, 4547-4551; Karin, M. (1999) J. Biol. Chem. 274, 27339-27342). The catalytic subunits, IKK1 and IKK2, are similar structurally as well as enzymatically and exist as a heterodimer in a large protein complex referred to as the IKK signalsome (Regnier, C., Song, H., Gao, X., Goeddel, D., Cao, Z. and Rothe, M. (1997) Cell 90, 373-383; DiDonato, J. A., Hayakawa, M., Rothwarf, D. M., Zandi, E. and Karin, M. (1997) Nature 388, 548-554; Mercurio, F., Zhu, H., Murray, B. W., Shevchenko, A., Bennett, B. L., Li, J. W., Young, D. B., Barbosa, M., Mann, M., Manning, A. and Roa, A. (1997) Science 278, 860-866; Zandi, E. Rothwarf, D. M., Delhase, M., Hayadawa, M and Karin, M. (1997) Cell 91, 243-252; Woronicz, J. D., Gao, X., Cao, Z., Rothe, M. And Goeddel, D. V. (1997) Science 278, 866-869). A third protein, NEMO (IKKγ, IKKAP1), is a regulatory adapter protein necessary for IKK activation and kinase activity (Yamaoka, S., Courtois, G., Bessia, C., Whiteside, S. T., Weil, R., Agou, F., Kirk, H. E., Kay, R. J., and Ireal, A. (1998) Cell 93, 1231-1240; Rothwarf, D. M., Zandi, E., Natoli, G., Karin, M. (1998) Nature 395, 297; Mercurio, F., Murray, B. W., Shevchenko, A., Bennet, B. L., Young, D. B., Li, J. W., Pascual, G., Motiwala, A., Zhu, H., Mann, M and Manning, A. M. (1999) Mol. Cell. Biol. 2, 1526-1538). IKK1 and IKK2 are co-expressed in most human adult tissues as well as in different developmental stages of mouse embryos (Regnier, C., Song, H., Gao, X., Goeddel, D., Cao, Z. and Rothe, M. (1997) Cell 90, 373-383; DiDonato, J. A., Hayakawa, M., Rothwarf, D. M., Zandi, E. and Karin, M. (1997) Nature 388, 548-554; Mercurio, F., Zhu, H., Murray, B. W., Shevchenko, A., Bennett, B. L., Li, J. W., Young, D. B., Barbosa, M., Mann, M., Manning, A. and Roa, A. (1997) Science 278, 860-866; Zandi, E. Rothwarf, D. M., Delhase, M., Hayadawa, M and Karin, M. (1997) Cell 91, 243-252; Woronicz, J. D., Gao, X., Cao, Z., Rothe, M. and Goeddel, D. V. (1997) Science 278, 866-869; Hu, M. C. T., and Wang, Y. (1998) Gene 222, 31-40). This kinase complex appears to represent a critical, common denominator in the activation of NF-κB in a number of signal transduction pathways stimulated by a variety of agonists including cytokines, such as TNFα and IL1β, microbial products such as LPS and viral proteins such as TAX, as well as phorbol esters, oxidizing agents and serine/tyrosine phosphatases (Ghosh S., May, M. J., and Kopp. E (1998) Annu. Rev. Immunol. 16, 115-260; Zandi, E., and Karin, M. (1999) Mol. Cell. Biol. 19, 4547-4551; Karin, M. (1999) J. Biol. Chem. 274, 27339-27342).
IKK1 (also termed IKKα; Regnier, C., Song, H., Gao, X., Goeddel, D., Cao, Z. and Rothe, M. (1997) Cell 90, 373-383; DiDonato, J. A., Hayakawa, M., Rothwarf, D. M., Zandi, E. and Karin, M. (1997) Nature 388, 548-554; Mercurio, F., Zhu, H., Murray, B. W., Shevchenko, A., Bennett, B. L., Li, J. W., Young, D. B., Barbosa, M., Mann, M., Manning, A. And Roa, A. (1997) Science 278, 860-866) was cloned simultaneously by standard biochemical purification of the IκB kinase activity from TNFα stimulated HeLa S3 cells and by its interaction with the MAP3K, NF-κB inducing kinase (NIK), in a yeast two-hybrid screen. IKK1 was identified as the previously cloned serine-threonine kinase, CHUK (Connelly, M. and Marcu, K. (1995) Cell. Mol. Biol. Res. 41, 537-549). IKK1 (also termed IKKα) is an 85 kDa, 745 amino acid protein that contains an N-terminal serine/threonine kinase catalytic domain, a leucine zipper-like amphipathic helix, and a C-terminal helix-loop-helix domain. IKK2 (also termed IKKβ) was also cloned by standard biochemical purification, copurifying with IKK1 from TNFα stimulated HeLa S3 cells as well as by being identified in the public database from an EST clone with sequence homology to IKK1 (Mercurio, F., Zhu, H., Murray, B. W., Shevchenko, A., Bennett, B. L., Li, J. W., Young, D. B., Barbosa, M., Mann, M., Manning, A. and Roa, A. (1997) Science 278, 860-866; Zandi, E. Rothwarf, D. M., Delhase, M., Hayadawa, M and Karin, M. (1997) Cell 91, 243-252; Woronicz, J. D., Gao, X., Cao, Z., Rothe, M. And Goeddel, D. V. (1997) Science 278, 866-869). IKK2 is an 87 kDa, 756 amino acid protein with the same over all topology as IKK1 except for the addition of an 11 amino acid extension at the C-terminus. IKK1 and IKK1 are 52% identical overall with 65% identity in the kinase domain and 44% identity in the protein interaction domains in the C-terminus. Data obtained using transient mammalian expression analysis, by in vitro translation experiments and by coexpression in a baculoviral system reveals that IKK1 and IKK2 associate preferentially as a heterodimer through their leucine zipper motifs. Although homodimers have also been described in these systems, the heterodimer is thought to be the physiologic form of the kinase in mammalian cells (Zandi, E. Rothwarf, D. M., Delhase, M., Hayadawa, M and Karin, M. (1997) Cell 91, 243-252; Li, J., Peet, G. W., Pullen, S. S., Schembri-King, J., Warren, T. C., Marcu, K. B., Kehry, M. R., Barton, R. and Jakes, S. (1998) J. Biol. Chem. 273, 30736-30741). Finally, NEMO (also termed IKKγ) contains three α-helical regions including a leucine zipper, interacts preferentially with IKK2 and is required for activation of the heterodimeric kinase complex perhaps by bringing other proteins into the signalsome complex (Yamaoka, S., Courtois, G., Bessia, C., Whiteside, S. T., Weil, R., Agou, F., Kirk, H. E., Kay, R. J., and Ireal, A. (1998) Cell 93, 1231-1240; Rothwarf, D. M., Zandi, E., Natoli, G., Karin, M. (1998) Nature 395, 297; Mercurio, F., Murray, B. W., Shevchenko, A., Bennet, B. L., Young, D. B., Li, J. W., Pascual, G., Motiwala, A., Zhu, H., Mann, M and Manning, A. M. (1999) Mol. Cell. Biol. 2, 1526-1538).
The kinase activities of IKK1 and IKK2 are regulated by phosphorylation and require an intact leucine zipper (LZ) for dimerization as well as an intact helix-loop-helix (HLH) domain, which can exert a positive regulatory effect on kinase activity even when it is expressed in trans with the remainder of the IKK protein (Regnier, C., Song, H., Gao, X., Goeddel, D., Cao, Z. and Rothe, M. (1997) Cell 90, 373-383; DiDonato, J. A., Hayakawa, M., Rothwarf, D. M., Zandi, E. and Karin, M. (1997) Nature 388, 548-554; Mercurio, F., Zhu, H., Murray, B. W., Shevchenko, A., Bennett, B. L., Li, J. W., Young, D. B., Barbosa, M., Mann, M., Manning, A. and Roa, A. (1997) Science 278, 860-866; Zandi, E. Rothwarf, D. M., Delhase, M., Hayadawa, M and Karin, M. (1997) Cell 91, 243-252; Woronicz, J. D., Gao, X., Cao, Z., Rothe, M. and Goeddel, D. V. (1997) Science 278, 866-869; Dehase, M., Hayakawa, M., Chen, Y., and Karin, M. (1999) Science 284, 309-313). Both IKK subunits contain a canonical MAPKK activation loop motif near the N-terminus which is the target for phosphorylation and activation of kinase activity by MAP3Ks such as NIK and MEKK1, although the physiologic regulation by these two upstream kinases awaits further characterization (Zandi, E., and Karin, M. (1999) Mol. Cell. Biol. 19, 4547-4551; Karin, M. (1999) J. Biol. Chem. 274, 27339-27342; Karin, M., and Delhase, M. (1998) Proc. Natl. Acad. Sci. USA 95, 9067-9069). Finally, phosphorylation of serines in the C-terminus of IKK2 results in a decrease in IKK activity and it is postulated to be responsible for the transient kinase activity seen after stimulation of cells with an agonist (Dehase, M., Hayakawa, M., Chen, Y., and Karin, M. (1999) Science 284, 309-313).
IKK2 demonstrates a more potent kinase activity compared to IKK1 using IκBα or IκBβ as a substrate (Mercurio, F., Zhu, H., Murray, B. W., Shevchenko, A., Bennett, B. L., Li, J. W., Young, D. B., Barbosa, M., Mann, M., Manning, A. and Roa, A. (1997) Science 278, 860-866; Zandi, E. Rothwarf, D. M., Delhase, M., Hayadawa, M and Karin, M. (1997) Cell 91, 243-252; Woronicz, J. D., Gao, X., Cao, Z., Rothe, M. and Goeddel, D. V. (1997) Science 278, 866-869; Dehase, M., Hayakawa, M., Chen, Y., and Karin, M. (1999) Science 284, 309-313). Mutations of the phospho-acceptor serine residues within the MAPKK activation loop alters IKK2 kinase activity; the serine to alanine substitutions result in decreased kinase activity whereas the serine to glutamic acid substitutions result in a constitutively active kinase. Similar alanine mutations in IKK1 do not result in a decreased stimulation of total IKK activity in response to TNFα or ILL1β (Dehase, M., Hayakawa, M., Chen, Y., and Karin, M. (1999) Science 284, 309-313). IKK2 being the dominant kinase activity within the IKK complex is further supported by the analysis of fibroblasts from mice deficient in IKK1 or IKK2. Fibroblasts lacking IKK1 retain full IKK activity in response to cytokines and could activate NF-κB. In contrast, fibroblasts lacking IKK2 do not exhibit IKK activity when stimulated with cytokines nor do they activate NF-κB. Furthermore, the phenotypes of each IKK knock out is unique with IKK1 deficiency resulting in skin and skeletal defects and IKK2 knock out being embryonic lethal due to hepatocyte apoptosis (Li, Q., Antwerp, D. V., Mercurio, F., Lee, K., and Verma, I. M. (1999) Science 284, 321-325; Takeda, K., Tekeuchi, O., Tsujimura, T., Itami, S., Adachi, O., Kawai, T., Sanjo, H., Yoshikawa, K., Terada, N, and Akira, S. (1999) Science 284, 313-316; Hu, Y., Baud, V., Delhase, M., Zhang, P., Deerinck, T., Ellisman, M., Johnson, R., and Karin, M. (1999) Science 284, 315-320; Li, Q., Lu, Q., Hwang, J. Y., Buscher, D., Lee, K., Izpisua-Belmonte, J. C., and Verma, I. M. (1999) Gene and Development 13, 1322-1328; Tanaka, M., Fuentes, M. E., Yamaguchi, K., Durnin, M. H., Dalrymple, S. A., Hardy, K. L., and Goeddel, D. V. (1999) Immunity 10, 421-429).
It is well-known that NF-KB plays a key role in the regulated expression of a large number of pro-inflammatory mediators including cytokines such as IL-6 and IL-8, cell adhesion molecules, such as ICAM and VCAM, and inducible nitric oxide synthase (iNOS). Such mediators are known to play a role in the recruitment of leukocytes at sites of inflammation and in the case of iNOS, may lead to organ destruction in some inflammatory and autoimmune diseases. The importance of
NF-κB in inflammatory disorders is further strengthened by studies of airway inflammation including asthma in which NF-κB has been shown to be activated. This activation may underlie the increased cytokine production and leukocyte infiltration characteristic of these disorders. In addition, inhaled steroids are known to reduce airway hyper responsiveness and suppress the inflammatory response in asthmatic airways. In light of the recent findings with regard to glucocorticoid inhibition of NF-κB, one may speculate that these effects are mediated through an inhibition of NF-κB. Further evidence for a role of NF-κB in inflammatory disorders comes from studies of rheumatoid synovium. Although NF-κB is normally present as an inactive cytoplasmic complex, recent immunohistochemical studies have indicated that NF-κB is present in the nuclei, and hence active, in the cells comprising rheumatoid synovium. Furthermore, NF-κB has been shown to be activated in human synovial cells in response to stimulation with TNF-α. Such a distribution may be the underlying mechanism for the increased cytokine and eicosanoid production characteristic of this tissue. See Roshak, A. K., et al., J. Biol. Chem., 271, 31496-31501 (1996).
The NF-κB/Rel and IκB proteins are also likely to play a key role in neoplastic transformation. Family members are associated with cell transformation in vitro and in vivo because of overexpression, gene amplification, gene rearrangements, or translocations (Gilmore T D, Trends Genet 7:318-322, 1991; Gillmore T D, Oncogene 18:6925-6937, 1999; Rayet B. et al., Oncogene 18: 6938-6947, 1991). In addition, rearrangement and/or amplification of the genes encoding these proteins are seen in 20-25% of certain human lymphoid tumors. In addition, a role for NF-κB in the regulation of apoptosis, cell cycle progression, invasion, and metastasis has been reported (Bours V. et al., Biochemical Pharmacology 60:1085-1090, 2000) strengthening the role of this transcription factor in the control of cell proliferation. The inhibition of NF-κB has been shown to potentiate TNF- and cancer therapy through increased apoptosis (Wang C-Y et al., Science 274:784-787, 1996; Wang C-Y et al., Nat Med 5:412-417, 1999). It has also been shown that human T-cell leukemia virus type 1 (HTLV1) infected cells (the etiological agent of an aggressive malignancy of activated CD4+ T lymphocytes), IKKα and IKKβ are expressed constitutively, which normally function in a transient manner (Chu Z-L et al., J of Biological Chemistry 273:15891-15894, 1998). The HTLV1 transforming and transactivating protein (Tax) has been shown to bind MEKK1 and increases the activity of IKKβ to enhance phosphorylation of serine residues in IκBα that lead to its degradation.
U.S. Pat. No. 3,940,418 to R. Hamilton describes tricyclic 4,5-dihydrobenz[g]indazole-3-carboxylic acids as antiinflammatory agents.
U.S. Pat. No. 4,803,193 to Kanda et al, describes spiro[3-alkyl-1-aryl[1]benzopyrano[4,3-c]pyrazole-4(1H),9′-[9H]fluorenes as heat sensitive recording materials.
V. Colota et al (J. Med. Chem., 33, 2646 (1991)) describe tricyclic heteroaramatic systems, including 1-aryl-pyrazolo[4,5-c]quinolin-4-ones, 1-aryl-pyrazolo[4,5-c][1,8]naphthyridin-4-ones, and 1-aryl-[1]benzopyrano[3,4-d]pyrazol-4-ones for CNS applications. F. Melani et al [J. Med. Chem., 29, 291 (1986) also describe 1-phenyl-pyrazolo[4,5-c]quinolines for CNS applications.
U.S. Pat. Nos. 4,816,467 and 5,206,258 to Doria et al describe (2-cyano-3-(1,4-dihydro)-1-phenyl-[1]benzothiopyrano [4,3-c]pyrazol-3-yl)-3-oxo-propanamides as immunomodulators. G. Doria et al (Farmaco, 46, 843 (1991)) also describe the immunomodulating activity of pyrazolylpropanamides, and specifically ethyl[1-(4-fluorophenyl)-1,4-dihydro-[1]benzothiopyrano[4,3-c]pyrazole]-3-carboxylate. British patent 2,227,741 describes related benzopyrano[4,3-c]pyrazoles and benzothiopyrano[4,3-c]pyrazoles. European application No. 347,773 similarly describes such fused pyrazole compounds, and specifically α-cyano-N,1-bis(4-fluorophenyl)-β-oxo-1H-[1]benzothieno[3,2-c]pyrazole-3-propanamide. U.S. Pat. No. 5,260,328 to Doria et al describes 2-cyano-3-(1,4-dihydro)-1-phenyl-[1]benzothiopyrano[4,3-c]pyrazol-3-yl)-3-oxo-propanamides for the treatment of rheumatoid arthritis.
U.S. Pat. No. 4,678,499 to Pasteris et al describes 1-aryl-indenopyrazol-4-one-5-sulfonamides as having herbicidal activity. Specifically, 1-phenyl-indenopyrazol-4-one-5-sulfonamide and 1,4-dihydro-N-[[(4-methoxy-6-methyl-2-pyrimidinyl)amino]carbonyl]-3-methyl-1-[4-(methylsulfonyl)phenyl]-4-oxo-indeno[1,2-c]pyrazole-5-sulfonamide are described.
U.S. Pat. Nos. 5,547,975; 5,565,482; 5,670,532; and 5,886,016 to Talley et al. describe benzopyranopyrazolyl derivates for the treatment of inflammation. Fravolini, A. et al., describes substituted pyrazolyl compounds having anti-inflammatory activity (Farmco, Ed. Sci 33:855-856, 1978).